<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body{
            margin: 0;
            padding: 0;

        }
        .box{
            width: 300px;
            height: 150px;
            background-color: pink;
            margin: 20px auto;
        }
        .box:nth-child(1){
            border-radius: 50%;
        }
        .box:nth-child(2){
            border-radius: 150px 150px 0 0 ;
        }
        .box:nth-child(3){
            border-radius:100% 0 0 0;
        }
    
        .box:nth-child(4){
            border-radius:150px 0;
        }
    </style>
</head>
<body>
    <div class="box"></div>
    <div class="box"></div>
    <div class="box"></div>
    <div class="box"></div>
    
</body>
</html>